Polypropylene-based resin composition and automobile parts using the same

ABSTRACT

The present invention provides a polypropylene-based resin composition, which comprises of a) a polypropylene; b) an ethylene 1-octene copolymer in which r 1 r 2 &lt;1 (herein, r 1 =k 11 /k 12 , r 2 =k 22 /k 21 , k 11  is a growth reaction rate constant when ethylene is added to a growth chain in which an end active site is ethylene, k 12  is a growth reaction rate constant when octene is added to a growth chain in which an end active site is ethylene, k 22  is a growth reaction rate constant when octene is added to a growth chain in which an end active site is octene, and k 21  is a growth reaction rate constant when ethylene is added to a growth chain in which an end active site is octene); and c) an inorganic filling agent, and a part for vehicles manufactured by using the same.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 12/489,603, filed Jun. 23, 2009, which issued as U.S. Pat. No.8,604,125, which claims priority from Korean Patent Application No.10-2008-0060294, filed on Jun. 25, 2008, the disclosures of which areincorporated herein by reference.

The present invention relates to a polypropylene-based resin compositionand a part for vehicles using the same. More particularly, the presentinvention relates to a polypropylene-based resin composition for vehicleparts, which has high heat deflection temperature (HDT) and excellentflexural strength without a reduction in the other properties, that is,impact strength, elasticity, tensile property and the like, and a partfor vehicles using the same.

BACKGROUND OF THE INVENTION

In general, a composition for interior and exterior deco parts ofvehicles is mainly composed of polypropylene (PP) and apolypropylene-based resin composition that includes an impact modifierand an inorganic filler has been used.

Before the middle of 1990's at which an ethylene α-olefine copolymerthat is polymerized by applying a metallocene catalyst was developed, asthe material of the interior and exterior decos of vehicles,particularly, a material of a bumper cover, a polypropylene-based resincomposition which is mixed with EPR or EPDM as an impact modifier wasmainly used. However, after the ethylene α-olefine copolymer that ismanufactured by the metallocene catalyst has been used, as an impactmodifier, the ethylene α-olefine copolymer starts to be used, andrecently, the ethylene α-olefine copolymer has been mainly used. Thereason for this is that the polypropylene-based complex material usingthis has uniform properties such as impact strength, elasticity, bendingstrength and the like, and good shapability, and is low-priced.

Since polyolefine that is synthesized by the metallocene catalyst isuniformly controlled in terms of molecular structure as compared to theZiegler-Natta catalyst, it has a narrow molecular weight distributionand excellent mechanical properties. Since in the case of the lowdensity ethylene elastomer which is polymerized by metallocene catalyst,the α-olefine copolymerization monomer is relatively uniformly insertedinto the polyethylene (PE) molecule as compared to the use of theZiegler-Natta catalyst, while low density rubber properties aremaintained, excellent other mechanical properties are ensured.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide apolypropylene-based resin composition that is used for manufacturingvehicle parts which have high heat deflection temperature and excellentflexural strength without a reduction in the other properties, and apart for vehicles that is manufactured by using the same.

The present invention provides a polypropylene-based resin composition,which comprises a) a polypropylene; b) an ethylene 1-octene copolymer inwhich r₁r₂<1; and c) an inorganic filler. Herein, r₁ and r₂ are definedby using the following Equations.r ₁ =k ₁₁ /k ₁₂r ₂ =k ₂₂ /k ₂₁

k₁₁: a growth reaction rate constant when ethylene is added to a growthchain in which an end active site is ethylene,

k₁₂: a growth reaction rate constant when octene is added to a growthchain in which an end active site is ethylene,

k₂₂: a growth reaction rate constant when octene is added to a growthchain in which an end active site is octene,

k₂₁: a growth reaction rate constant when ethylene is added to a growthchain in which an end active site is octene).

It is preferable that b) the ethylene 1-octene copolymer in which r₁r₂<1has a molecular weight distribution (Mw/Mn) that is less than 3.5 and adensity that is defined by the following Equation.10³ ×d≦−1.8×A+937

Herein, d is a density of a copolymer and A is wt % of 1-octene in thecopolymer.

The ethylene 1-octene copolymer may be manufactured by using thetransition metal compound that is represented by the following Formula1.

wherein,

R1, R1′, R2, R2′, R3, R3′ and R3″ are the same as or different from eachother, and each independently hydrogen; a halogen radical; an alkylradical having 1 to 20 carbon atoms, an aryl radical having 6 to 20carbon atoms or a silyl radical; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl radical having 7 to 20 carbon atoms or anarylalkyl radical having 7 to 20 carbon atoms; or a Group 14 metalloidradical substituted with hydrocarbyl having 1 to 20 carbon atoms; or analkoxy radical having 1 to 20 carbon atoms, an aryloxy radical having 6to 20 carbon atoms or an amino radical, and two or more of them may beconnected to each other by an alkylidene radical containing an alkylradical having 1 to 20 carbon atoms or an aryl radical having 6 to 20carbon atoms to form an aliphatic or aromatic ring;

CY1 is a substituted or unsubstituted aliphatic or aromatic ring, inwhich CY1 may be substituted with hydrogen; a halogen radical; or analkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to20 carbon atoms, and two or more substituents may be connected to eachother to form an aliphatic or aromatic ring;

M is a Group 4 transition metal; and

Q1 and Q2 are the same as or different from each other, and eachindependently a halogen radical; an alkyl amido radical having 1 to 20carbon atoms or an aryl amido radical having 6 to 20 carbon atoms; analkyl radical having 1 to 20 carbon atoms, an alkenyl radical having 2to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, analkylaryl having 7 to 20 carbon atoms or arylalkyl radical having 7 to20 carbon atoms; or alkylidene radical having 1 to 20 carbon atoms.

The polypropylene-based resin composition according to the presentinvention has excellent mechanical strength, that is, flexural strength,tensile strength, and elongation as compared to a known composition. Inparticular, since the resin has high heat deflection temperature (HDT),it can well endure hot environment and the summer climate. In the caseof when the polypropylene-based resin composition according to thepresent invention is used as interior and exterior decos of vehicles,such as bumper covers of vehicles, since a thickness of a shaped bodycan be reduced, the shaped body can be reduced in views of weight.

DETAILED DESCRIPTION

Hereinafter, the present invention will be described in more detail.

The present invention relates to a polypropylene-based resin compositionthat includes a polypropylene, an impact modifier, and an inorganicfiller, and is characterized in that an ethylene 1-octene copolymer inwhich r₁r₂<1 is used as the impact modifier. Herein, r₁ and r₂ aredefined by using the following Equations.r ₁ =k ₁₁ /k ₁₂r ₂ =k ₂₂ /k ₂₁

k₁₁: a growth reaction rate constant when ethylene is added to a growthchain in which an end active site is ethylene,

k₁₂: a growth reaction rate constant when octene is added to a growthchain in which an end active site is ethylene,

k₂₂: a growth reaction rate constant when octene is added to a growthchain in which an end active site is octene,

k₂₁: a growth reaction rate constant when ethylene is added to a growthchain in which an end active site is octene.

The r₁r₂ is an index that indicates the degree of uniform distributionof ethylene and octene in the ethylene 1-octene copolymer, and thecopolymer in which r₁r₂<1 has a uniform comonomer distribution unlike aknown ethylene copolymer that has a random or block structure comonomerdistribution, such that it is possible to manufacture the copolymerhaving lower density at the same comonomer content and a relativelysmall amount of octene may be used in order to obtain the copolymerhaving the same density.

In particular, it is preferable that the ethylene 1-octene copolymer hasthe density that is defined by the following Equation. In the case ofwhen the density satisfies the following Equation, as compared to theknown copolymer, the lower density may be ensured at the same comonomercontent.10³ ×d≦−1.8×A+937

Herein, d is a density of a copolymer and A is wt % of 1-octene in thecopolymer.

As described above, the polypropylene-based resin composition thatincludes the ethylene 1-octene copolymer as the impact modifier mayprovide vehicle parts that has high heat deflection temperature andflexural strength without reduction in other properties, such as impactstrength, elasticity, tensile property, as compared to thepolypropylene-based resin composition that includes EPR, EPDM rubber orthe known ethylene α-olefine copolymer.

The ethylene 1-octene copolymer may be an alternative copolymer, a blockcopolymer or a random copolymer, and among them, the random copolymer ispreferable.

Mw/Mn of the ethylene 1-octene copolymer is preferably less than 3.5,more preferably not more than 3.0. In the case of when Mw/Mn is withinthe above range, it is advantageous in views of the less smell problemof the copolymer and good mechanical property.

In addition, the density of the ethylene 1-octene copolymer ispreferably 0.9 g/cm³ or less, and more preferably in the range of 0.86to 0.88 g/cm³. In the case of when the density is in the above range, itis advantageous in views of elasticity and impact strength.

In addition, the ethylene 1-octene copolymer has a melt index (MI)preferably in the range of 0.1 to 70 g/10 min and more preferably in therange of 0.5 to 10 g/10 min. In addition, the ethylene 1-octenecopolymer has the molecular weight (Mw) preferably in the range of20,000 to 1,000,000 and more preferably in the range of 50,000 to500,000. This component is included preferably in the range of 10 to 40wt % and more preferably in the range of 20 to 30 wt % in the totalcomposition.

In the ethylene 1-octene copolymer, the molar ratio of ethylene:1-octenemay be in the range of 1:99 to 99:1. In addition, the content ofethylene in the ethylene 1-octene copolymer is preferably in the rangeof 50 to 99 wt %, more preferably in the range of 55 to 80 wt %, andmost preferably in the range of 55 to 75 wt %. In the case of when thecontent of ethylene is in the above range, it is advantageous in viewsof high HDT and flexural strength without reduction in other properties,such as impact strength, elasticity, tensile property and the like.

The ethylene 1-octene copolymer that has the above properties is athermoplastic elastomer (TPE), which may be manufactured by using anactivated catalyst composition that includes a Group IV transition metalcompound which is coordinated with a monocyclopentadienyl ligand towhich a quinoline-based amino group is introduced.

In this manufacturing process, a continuous solution polymerizationprocess that can perform polymerization at a wide temperature andpressure range may be used. The Group IV transition metal compound whichis coordinated with a monocyclopentadienyl ligand to which aquinoline-based amino group is introduced may be represented by theabove Formula 1.

In Formula 1, preferably, R1, R1′, R2, and R2′ are each independentlyhydrogen; an alkyl radical having 1 to 20 carbon atoms, an aryl radicalhaving 6 to 20 carbon atoms or a silyl radical; an alkenyl radicalhaving 2 to 20 carbon atoms, an alkylaryl radical having 7 to 20 carbonatoms, or an arylalkyl radical having 7 to 20 carbon atoms; or ametalloid radical of Group 14 metal that is substituted by hydrocarbylhaving 1 to 20 carbon atoms, and two or more of R1, R1′, R2, and R2′ maybe connected to each other by an alkylidine radical that includes analkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to20 carbon atoms to form a ring, and

R3, R3′ and R3″ are each independently hydrogen; a halogen radical; oran alkyl radical having 1 to 20 carbon atoms, an aryl radical having 6to 20 carbon atoms, an alkoxy radical having 1 to 20 carbon atoms, anaryloxy radical having 6 to 20 carbon atoms, or an amino radical having6 to 20 carbon atoms, and two or more of R3, R3′ and R3″ may beconnected to each other to form an aliphatic or aromatic ring.

A preferable example of the compound represented by Formula 1 is acompound represented by following Formula 2:

wherein,

R4, R4′, R5, R5′ and R6 to R14 are the same as or different from eachother, and each independently hydrogen; a halogen radical; an alkylradical having 1 to 20 carbon atoms, an aryl radical having 6 to 20carbon atoms or a silyl radical; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl radical having 7 to 20 carbon atoms or anarylalkyl radical having 7 to 20 carbon atoms; or a Group 14 metalloidradical substituted with hydrocarbyl having 1 to 20 carbon atoms; or analkoxy radical having 1 to 20 carbon atoms, an aryloxy radical having 6to 20 carbon atoms or an amino radical, and two or more of them may beconnected to each other by an alkylidene radical containing an alkylradical having 1 to 20 carbon atoms or an aryl radical having 6 to 20carbon atoms to form an aliphatic or aromatic ring;

M is a Group 4 transition metal; and

Q3 and Q4 are the same as or different from each other, and eachindependently a halogen radical; an alkyl amido radical having 1 to 20carbon atoms or an aryl amido radical having 6 to 20 carbon atoms; analkyl radical having 1 to 20 carbon atoms, an alkenyl radical having 2to 20 carbon atoms, an aryl radical having 6 to 20 carbon atoms, analkylaryl having 7 to 20 carbon atoms or arylalkyl radical having 7 to20 carbon atoms; or alkylidene radical having 1 to 20 carbon atoms.

In Formula 2, preferably, R4, R4′, R5 and R5′ are each independentlyhydrogen; or an alkyl radical having 1 to 20 carbon atoms, an arylradical having 6 to 20 carbon atoms or a silyl radical; R6 to R14 areeach independently an alkyl radical having 1 to 20 carbon atoms or anaryl radical having 6 to 20 carbon atoms; an alkenyl radical having 2 to20 carbon atoms, an alkylaryl radical having 7 to 20 carbon atoms or anarylalkyl radical having 7 to 20 carbon atoms; or an alkoxy radicalhaving 1 to 20 carbon atoms, an aryloxy radical having 6 to 20 carbonatoms or an amino radical, and two or more of R6 to R14 may be connectedto form an aliphatic or aromatic ring; and Q3 and Q4 are eachindependently a halogen radical; an alkyl amido radical having 1 to 20carbon atoms or an aryl amido radical having 6 to 20 carbon atoms; or analkyl radical having 1 to 20 carbon atoms.

It is preferable that the compound that is represented by Formula 2 is acompound that is represented by the following Formula 3 or 4:

In Formula 3, the substituent groups are defined like Formula 2.

In Formula 4, the substituent groups are defined like Formula 2.

Of transition metal compound represented by Formula 1, preferredcompounds to control the electronic or steric environment around themetal, include transition metal compounds of following structures:

wherein, R15 and R15′ are each independently selected from hydrogen or amethyl radical; and Q5 and Q6 are each independently selected from amethyl radical, dimethylamido radical or chloride radical.

In the method of producing the polyolefin copolymer according to thepresent invention, one or more of the compounds that are represented bythe following Formulae 5 to 7 may be used in conjunction with thecompound that is represented by Formula 1:—[Al(R16)-O]_(a)—  Formula 5

wherein,

R16 are each independently a halogen radical; a hydrocarbyl radicalhaving 1 to 20 carbon atoms; or a hydrocarbyl radical having 1 to 20carbon atoms which is substituted with halogen; a is an integer of 2 ormore;D(R17)₃  Formula 6

wherein,

D is an aluminium or boron; R17 are each independently a halogenradical, a hydrocarbyl radical having 1 to 20 carbon atoms, or ahydrocarbyl radical having 1 to 20 carbon atoms which is substitutedwith halogen; and[L-H]⁺[ZA₄]⁻ or [L]⁺[ZA₄]⁻  Formula 7

wherein,

L is neutral or cationic Lewis acid; H is a hydrogen atom; Z is anelement of Group 13, such as B, Al, Ga, In, Ti and the like; and A areeach independently an aryl radical having 6 to 20 carbon atoms or analkyl radical having 1 to 20 carbon atoms, at least one hydrogen atom ofwhich is substituted with halogen, an hydrocarbyl radical having 1 to 20carbon atoms, an alkoxy radical having 1 to 20 carbon atoms or phenoxyradical.

In the present invention, the ethylene 1-octene copolymer that is usedas the impact modifier may be manufactured by manufacturing a catalystcomposition using the transition metal compound that is represented byFormula 1 and one or more compounds that are represented by Formulas 5to 7, and then polymerizing ethylene and octane by using them. Thecatalyst composition may be manufactured by using the following methodfor manufacturing the composition.

First, there is provided a method that comprises the steps of contactingthe transition metal complex compound that is represented by Formula 1and the compound that is represented by Formula 5 or Formula 6, suchthat a mixture is obtained; and adding the compound that is representedby Formula 7 to the mixture.

Second, there is provided a method that comprises the step of contactingthe transition metal complex compound that is represented by Formula 1and the compound that is represented by Formula 5, such that thecatalyst composition is manufactured.

Third, there is provided a method that comprises the step of contactingthe transition metal complex compound that is represented by Formula 1and the compound that is represented by Formula 7, such that thecatalyst composition is manufactured.

In the first method among the methods for producing the catalyticcomposition, the molar ratio of the transition metal compound of theFormula 1 and the compound represented by the Formula 5 or 6 ispreferably 1:2 to 1:5,000, more preferably 1:10 to 1:1,000, and mostpreferably 1:20 to 1:500. In the case of when the molar ratio is in theabove range, since the amount of the alkylating agent is sufficient, thealkylating of the metal compound may be completely carried out. And sidereactions between the remaining alkylating agent in the excessive amountand an activating agent of Formula 7 may be minimized.

Next, the molar ratio of the transition metal compound that isrepresented by the Formula 1 and the compound that is represented by theFormula 7 is preferably 1:1 to 1:25, more preferably 1:1 to 1:10, andmost preferably 1:2 to 1:5. In the case of when the molar ratio is inthe above range, since the amount of the activation agent is sufficient,the activation of the transition metal compound may be completelyperformed, thus the activity of the produced catalytic composition maybe remained highly. Also, the amount of the remaining activation agentis not too large. Accordingly, the cost of the catalytic composition iseconomic and the purity of the polymer is good.

In the second method for producing the catalytic composition, the molarratio of the transition metal compound of the Formula 1 and the compoundthat is represented by the Formula 5 is preferably 1:10 to 1:10,000,more preferably 1:100 to 1:5,000, and most preferably 1:500 to 1:2,000.In the case of when the molar ratio is in the above range, since theamount of the activation agent is sufficient, the activation of themetal compound may be completely performed, thus the activity of theproduced catalytic composition may be remained highly. Also, the amountof the remaining activation agent is not too large. Accordingly, thecost of the catalytic composition is economic and the purity of thepolymer is good.

Meanwhile, in the third method for producing the catalytic composition,the molar ratio of the transition metal compound of the Formula 1 andthe compound that is represented by the Formula 7 is preferably 1:1 to1:25, more preferably 1:1 to 1:10, and most preferably 1:2 to 1:5. Inthe case of when the molar ratio is in the above range, since the amountof the activation agent is sufficient, the activation of the metalcompound may be completely performed, thus the activity of the producedcatalytic composition may be remained highly. Also, the amount of theremaining activation agent is not too large. Accordingly, the cost ofthe catalytic composition is economic and the purity of the polymer isgood.

In the production of the activated catalytic composition, as thereaction solvent, a hydrocarbon solvent such as pentane, hexane,heptane, etc., or an aromatic solvent such as benzene, toluene, etc. canbe used. However, the reaction solvent is not limited to the above, andall the solvent that is available in the art may be used.

In addition, the transition metal compounds that are represented byFormula 1 and the cocatalysts may be used as supported on silica oralumina.

Preferable examples of the compound represented by Formula 5 aremethylaluminoxane, ethylaluminoxane, isobutylaluminoxane,butylaluminoxane etc., and more preferable compound ismethylaluminoxane, but not limited thereto if it is andalkylaluminoxane.

Examples of the compound represented by Formula 6 includetrimethylaluminium, triethylaiuminium, triisobutylaluminum,tripropylaluminium, tributylaluminium, dimethylchloroaluminum,triisopropylaluminum, tri-s-butylaluminium, tricyclopentylaluminium,tripentylaluminium, triisopentylaluminium, trihexylaluminium,trioctylaluminum, ethyldimethylaluminium, methyldiethylaiuminium,triphenylaluminium, tri-p-tolylaluminium, dimethylaluminiummethoxide,dimethylaluminiumethoxide, trimethylboron, triethylboron,triisobutylboron, tripropylboron, tributylboron, and so on, and morepreferable compound is selected from trimethylaluminium,triethylaluminium and triiobutylaluminium, but not limited thereto.

Examples of the compound represented by Formula 7 includetriethylammonium tetraphenyl boron, tributylammonium tetraphenyl boron,trimethylammonium tetraphenyl boron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl) boron, trimethylammoniumtetra(o, p-dimethylphenyl) boron, tributylammoniumtetra(p-trifluoromethylphenyl) boron, trimethylammoniumtetra(p-trifluoromethylphenyl) boron, tributylammoniumtetrapentafluorophenyl boron, N,N-diethylanilinium tetraphenyl boron,N,N-diethylanilinium tetraphenyl boron, N,N-diethylaniliniumtetrapentafluorophenyl boron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenyl boron, trimethylphosphoniumtetraphenyl boron, triethylammonium tetraphenyl aluminium, tributylammonium tetraphenyl aluminium, trimethylammonium tetraphenyl aluminum,tripropylammonium tetraphenyl aluminum, trimethylammonium tetra(p-tolyl)aluminium, tripropylammonium tetra(p-tolyl) aluminium, triethylammoniumtetra(o, p-dimethylphenyl) aluminium, tributyl ammoniumtetra(p-trifluoromethylphenyl) aluminium, trimethylammoniumtetra(p-trifluoromethylphenyl) aluminium, tributylammoniumtetrapentafluorophenyl aluminium, N,N-diethylanilinium tetraphenylaluminium, N,N-diethylanilinium tetrapentafluorophenyl aluminium,diethylammonium tetrapentafluorophenyl aluminium, triphenylphosphoniumtetraphenyl aluminium, trimethylphosphonium tetraphenyl aluminium,tripropylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl) boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, N,N-diethylanilinium tetraphenyl boron, triphenylcarboniumtetra(p-trifluoromethylphenyl) boron, triphenylcarboniumtetrapentafluorophenyl boron, and the like.

In the polymerization of the ethylene 1-octene copolymer that is used asthe impact modifier in the present invention, the most preferablepolymerization process using the catalyst composition that includes thecompound that is represented by Formula 1 is a solution process, and ifthe this composition is used in conjunction with an inorganic carriersuch as silica, it may be applied to a slurry or gas-phase process.

The catalyst composition may be introduced by dissolving or diluting itto an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, forexample, pentane, hexane, heptane, nonane, decane, and their isomers; anaromatic hydrocarbon solvent such as toluene, benzene; a hydrocarbonsolvent that is substituted with chlorine atom such as dichloromethane,chlorobenzene, etc. It is preferable to use the solvent after removing alittle water or air which acts as a catalyst poison, by treating thesolvent with a little alkylaluminium. It is also possible to addco-catalyst to the solvent.

The catalyst composition for manufacturing the ethylene 1-octenecopolymer that is used in the present invention is described in detailin Korean Patent Application No. 10-2006-26992 which is applied by thepresent applicator on Mar. 24, 2006, and all contents of this documentare incorporated in the present specification.

In the present invention, as the polypropylene, any thing that is usedin the art may be used without a limitation. For example, a highcrystalline homopolypropylene, a block copolymer that includes ethyleneor a mixture thereof may be used. Polypropylene is included preferablyin the range of 50 to 90 wt % on the basis of total composition and morepreferably in the range of 65 to 75 wt %.

In the present invention, as the inorganic filler, any thing that isused in the art may be used without a limitation. For example, talc,potassium carbonate, mica, clay and the like may be selected and usedaccording to the purpose thereof. The inorganic filler is includedpreferably in the range of 5 to 20 wt % on the basis of the totalcomposition and more preferably in the range of 7 to 12 wt %.

The polypropylene-based resin composition according to the presentinvention may further include an antioxidant, a UV stabilizer, a slipagent and the like in a small amount as other additives.

In the present invention, by using the above polypropylene-based resincomposition, it is possible to provide vehicle parts that have high heatdeflection temperature and flexural strength without a reduction inother properties, that is, impact strength, elasticity, and tensileproperty. As a method for manufacturing the vehicle parts, a technologythat is known in the art may be used. In the present invention, as thevehicle parts that can be manufactured by using the polypropylene-basedresin composition, any thing that is manufactured by using the knownpolypropylene-based resin composition may be included regardless of thekind thereof. For example, there are a bumper cover for vehicles, aglove box, a pillar and the like.

In the present invention, it may be provided a method for manufacturingvehicle parts by using the polypropylene-based resin composition. Themethod for manufacturing vehicle parts according to the presentinvention may include an injection molding method, an extrusion moldingmethod and the like which are well known in the art, but is not limitedthereto.

EXAMPLES

Hereinbelow, the present invention will be described in detail withreference to Examples. However, the following Examples are set forth toillustrate, but are not to be construed to limit the present invention.

The property evaluation method that is used in the present invention isdescribed in the following Table 1.

TABLE 1 Test methods and conditions Test item Method Condition DensityASTM D792 23° C. Melt Index (MI, 2.16 kg) ASTM D1238 2.16 kg, 190° C.Melting Point DSC¹⁾ Crystallinity DSC Heat Flow of Melting Peak DSCTensile Strength at Yield ASTM D638 50 mm/min Elongation at Break ASTMD638 50 mm/min Flexural Strength ASTM D790 ¼″, 10 mm/min FlexuralModulus ASTM D790 ¼″, 10 mm/min Izod Impact Strength, ASTM D256 ¼″, at23° C. and −30° C. notched Heat Deflection ASTM D648 4.6 kg Temperature¹⁾DSC: Differential Scanning Calorimetry

Property Evaluation of the Ethylene 1-Octene Copolymer

Physical properties of Engage™ 8200 manufactured by DOW, Co. and P8-750manufactured by LG Chemicals, Co., Ltd. which were the ethylene 1-octenecopolymer were measured, and the results thereof are described in thefollowing Table 1. P8-750 manufactured by LG Chemicals, Co., Ltd. wasmanufactured by using the catalyst compound (R4, R4′, R5′=methyl, M=Ti,Q3 & Q4=chloride) that was represented by Formula 4. In order to allowheat hysterises of polymers to be the same while the DSC measurement wasperformed, while the temperature was increased from normal temperatureto 150° C. at a rate of 10° C./min, maintained at that state for 3 min,cooled to −20° C. at a rate of 10° C./min, and increased to 150° C. at arate of 10° C./min, the measurement was carried out, such that the meltpeak which was the heat flow curve at the final step was analyzed. Theproperty evaluation results of ethylene 1-octene copolymer are describedin the following Table 2.

TABLE 2 Basic properties of the ethylene 1-octene copolymer Test itemDOW Engage ™ 8200 LG P8-750 Density 0.870 0.874 Melt Index (MI, 2.16 kg)5.0 4.0 r1 * r2 1.0 0.5 Melting point (° C.) 62.6 60.8 Crystallinity (%)12.4 14.4 Heat Flow of Melting Peak (J/g) 35.48 41.39 Mw/Mn 2.34 2.46Ethylene content (wt %) 36 35

The equivalent product manufactured by Dow, Co. (the ethylene octenecopolymer manufactured using the metallocene catalyst) and the ethyleneoctene copolymer that was used in the present invention were compared toeach other in respects to the basic properties such as the density, themelt index, and the DSC properties (melting point, and crystallinity),and as a result, as shown in Table 2, it could be confirmed that twocopolymers having similar densities have very different properties.

Example 1

70 wt % of the 1:1 mixture of HCPP (MI=100) manufactured by Hyosung,Co., Ltd. and CoPP (MI=40) manufactured by SK Chemicals, Co., Ltd. aspolypropylene, 20 wt % of P8-750 manufactured by LG Chemicals, Co., Ltd.as the ethylene 1-octene copolymer, 9 wt % of talc, and 1.0 wt % ofantioxidant (Irganox 1076) were used, such that the composition wasmanufactured. P8-750 of LG Chemicals, Co., Ltd. was manufactured byusing the catalyst compound (R4, R4′, R5′=methyl, M=Ti, Q3 &Q4=chloride) in which r1*r2=0.5 and which was represented by Formula 4.

In order to prepare the test sample for analyzing physical properties,after each component was uniformly mixed by using the Hensel mixer,palletizing was carried out by using the co-rotating twin ScrewExtruder, and the test sample was manufactured by using the injectionmachine. The physical properties of the manufactured test sample aredescribed in the following Table 3.

Comparative Example 1

The composition was manufactured, the test sample was manufactured, andphysical properties thereof was measured by using the same method asExample 1, except that Engage™ 8200 (r1*r2=1) manufactured by DOW, Co.was used as the ethylene 1-octene copolymer, and the evaluation resultsof the physical properties thereof are described in the following Table3.

TABLE 3 Test item Example 1 Comparative Example 1 Density (g/cm³) 0.8700.870 Melt Index (g/10 min) 5.0 5.0 Flexural Strength 244 224 (kg/cm²)Flexural Elaxticity 11,800 10,600 (kg/cm²) IZOD Impact   23° C. 39 39Strength (kgcm/cm) −30° C. 3.8 4.2 Tensile Strength (kg/cm²) 184 179Elongation (%) 220 140 HDT (° C.) 122 114

As described in Table 3, it could be seen that the sample manufacturedby using the polypropylene-based resin composition according to thepresent invention had the very excellent physical properties in terms ofthe flexural strength, the flexural elasticity, the tensile strength,the elongation, and the heat deflection temperature (HDT).

Example 2

The composition was manufactured, the test sample was manufactured, andphysical properties thereof was measured by using the same method asExample 1, except that LG-EOR-2 (r1*r2=0.5) manufactured by LGChemicals, Co., Ltd. was used as the ethylene 1-octene copolymer, andthe evaluation results of the physical properties thereof are describedin the following Table 4. LG-EOR-2 was manufactured by using thecatalyst compound (R4, R4′, R5′=methyl, M=Ti, Q3 & Q4=chloride) that wasrepresented by Formula 4.

Comparative Example 2

The composition was manufactured, the test sample was manufactured, andphysical properties thereof was measured by using the same method asExample 1, except that Engage™ 8180 (r1*r2=1) manufactured by DOW, Co.was used as the ethylene 1-octene copolymer, and the evaluation resultsof the physical properties thereof are described in the following Table4.

TABLE 4 Test item Example 2 Comparative Example 2 Density (g/cm³) 0.8650.863 Melt Index (g/10 min) 0.48 0.48 Flexural Strength (kg/cm²) 276 274Felxural Elasticity (kg/cm²) 15,760 14,874 IZOD Impact   23° C. 59 61Strength (kgcm/cm) −30° C. 5.8 5.9 Tensile Strength (kg/cm²) 177 177 HDT(° C.) 114 113

Example 3

The composition was manufactured, the test sample was manufactured, andphysical properties thereof was measured by using the same method asExample 1, except that LG-EOR-3 (r1*r2=0.6) manufactured by LGChemicals, Co., Ltd. was used as the ethylene 1-octene copolymer, andthe evaluation results of the physical properties thereof are describedin the following Table 5. LG-EOR-3 was manufactured by using thecatalyst compound (R4, R4′, R5′=methyl, M=Ti, Q3 & Q4=chloride) that wasrepresented by Formula 4.

Comparative Example 3

The composition was manufactured, the test sample was manufactured, andphysical properties thereof was measured by using the same method asExample 1, except that Engage™ 8130 (r1*r2=1) manufactured by DOW, Co.was used as the ethylene 1-octene copolymer, and the evaluation resultsof the physical properties thereof are described in the following Table5.

TABLE 5 Test item Example 3 Comparative Example 3 Density (g/cm³) 0.8700.865 Melt Index (g/10 min) 7.1 10.5 Flexural Strength (kg/cm²) 289 278Flexural Elasticity (kg/cm²) 16,537 15,530 IZOD Impact   23° C. 46 46Strength (kgcm/cm) −30° C. 4.5 4.6 Tensile Strength (kg/cm²) 184 180 HDT(° C.) 119 119

The polypropylene-based resin composition according to the presentinvention has excellent mechanical strength, that is, flexural strength,tensile strength, and elongation as compared to a known composition. Inparticular, since the resin has high heat deflection temperature (HDT),it can well endure hot environment and the summer climate. In the caseof when the polypropylene-based resin composition according to thepresent invention is used as interior and exterior decos of vehicles,such as bumper covers of vehicles, since a shaping thickness can bereduced, the shaped body can be reduced in views of weight.

The invention claimed is:
 1. A polypropylene-based resin composition,comprising: a) 65 to 75 wt % of a polypropylene; b) 10 to 40 wt % of anethylene 1-octene copolymer in which r₁r₂<1, wherein r₁=k₁₁/k₁₂,r₂=k₂₂/k₂₁, k₁₁ is a growth reaction rate constant when ethylene isadded to a growth chain in which an end active site is ethylene, k₁₂ isa growth reaction rate constant when octene is added to a growth chainin which an end active site is ethylene, k₂₂ is a growth reaction rateconstant when octene is added to a growth chain in which an end activesite is octene, and k₂₁ is a growth reaction rate constant when ethyleneis added to a growth chain in which an end active site is octene; and c)7 to 12 wt % of an inorganic filler, wherein the polypropylene-basedresin composition has a density of 0.865 to 0.870 g/cm³.
 2. Thepolypropylene-based resin composition of claim 1, wherein the ethylene1-octene copolymer in which r₁r₂<1 has a molecular weight distribution(Mw/Mn) of less than 3.5 and a density that is defined by Equation10³×d≦−1.8×A+937, wherein d is the density of the copolymer and A is wt% of 1-octene of the copolymer.
 3. The polypropylene-based resincomposition of claim 1, wherein the ethylene 1-octene copolymer in whichr₁r₂<1 has a density of 0.9 g/cm³ or less and a melt index (MI) in therange of 0.1 to 70 g/10 min.
 4. The polypropylene-based resincomposition of claim 1, wherein the ethylene 1-octene copolymer in whichr₁r₂<1 is manufactured by using a catalyst composition that includes atransition metal compound that is represented by the following Formula1:

wherein R1, R1′, R2, R2′, R3, R3′ and R3″ are the same as or differentfrom each other, and are independently hydrogen; a halogen radical; analkyl radical having 1 to 20 carbon atoms, an aryl radical having 6 to20 carbon atoms or silyl radical; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl radical having 7 to 20 carbon atoms, or anarylalkyl radical having 7 to 20 carbon atoms; a metalloid radical ofGroup 14 metal that is substituted by hydrocarbyl having 1 to 20 carbonatoms; or an alkoxy radical having 1 to 20 carbon atoms, an aryloxyradical having 6 to 20 carbon atoms or amino radical, and two or more ofR1, R1′, R2, R2′, R3, R3′ and R3″ may be connected to each other by analkylidine radical that includes an alkyl radical having 1 to 20 carbonatoms or an aryl radical having 6 to 20 carbon atoms to form analiphatic or aromatic ring, CY1 is a substituted or unsubstitutedaliphatic or aromatic ring, when substituted, a substituent group thatis substituted at CY1 is hydrogen; a halogen radical; or an alkylradical having 1 to 20 carbon atoms or an aryl radical having 6 to 20carbon atoms, and in the case of when there are a plurality ofsubstitutent groups, two or more substituent groups of the substituentgroups may be connected to each other to form an aliphatic or aromaticring; M is a Group IV transition metal; Q1 and Q2 are the same as ordifferent from each other, and are independently a halogen radical; analkylamido radical having 1 to 20 carbon atoms or an arylamido radicalhaving 6 to 20 carbon atoms; an alkyl radical having 1 to 20 carbonatoms, alkenyl radical having 2 to 20 carbon atoms, aryl radical having6 to 20 carbon atoms, alkylaryl radical having 7 to 20 carbon atoms orarylalkyl radical having 7 to 20 carbon atoms; or an alkylidene radicalhaving 1 to 20 carbon atoms.
 5. The polypropylene-based resincomposition of claim 4, wherein the compound that is represented byFormula 1 is a compound that is represented by the following Formula 2:

wherein R4, R4′, R5, R5′, and R6 to R14 are the same as or differentfrom each other, and are independently hydrogen; a halogen radical; analkyl radical having 1 to 20 carbon atoms, an aryl radical having 6 to20 carbon atoms or silyl radical; an alkenyl radical having 2 to 20carbon atoms, an alkylaryl having 7 to 20 carbon atoms, or an arylalkylradical having 7 to 20 carbon atoms; a metalloid radical of Group 14metal that is substituted by hydrocarbil having 1 to 20 carbon atoms; oran alkoxy radical having 1 to 20 carbon atoms, or an aryloxy radicalhaving 6 to 20 carbon atoms or amino radical, and two or more of themmay be connected to each other by an alkylidine radical that includes analkyl radical having 1 to 20 carbon atoms or an aryl radical having 6 to20 carbon atoms to form an aliphatic or aromatic ring, M is a Group IVtransition metal; Q3 and Q4 are the same as or different from eachother, and are independently a halogen radical; an alkylamido radicalhaving 1 to 20 carbon atoms or an arylamido radical having 6 to 20carbon atoms; an alkyl radical having 1 to 20 carbon atoms, alkenylradical having 2 to 20 carbon atoms, aryl radical having 6 to 20 carbonatoms, alkylaryl radical having 7 to 20 carbon atoms or arylalkylradical having 7 to 20 carbon atoms; or an alkylidene radical having 1to 20 carbon atoms.
 6. The polypropylene-based resin composition ofclaim 5, wherein the compound that is represented by Formula 2 is acompound that is represented by the following Formula 3 or Formula 4:

wherein the substituent groups are the same as those of Formula
 2. 7.The polypropylene-based resin composition of claim 4, wherein thecatalyst composition further comprises one or more of compounds that arerepresented by the following Formulae 5, 6, and 7:—[Al(R16)-O]_(a)—  Formula 5 wherein, R16 are each independently ahalogen radical, a hydrocarbyl radical having 1 to 20 carbon atoms, or ahydrocarbyl radical having 1 to 20 carbon atoms which is substitutedwith halogen, a is an integer of 2 or more;D(R17)₃  Formula 6 wherein, D is an aluminium or boron, R17 are eachindependently a halogen radical, a hydrocarbyl radical having 1 to 20carbon atoms, or a hydrocarbyl radical having 1 to 20 carbon atoms whichis substituted with halogen; and[L-H]⁺[ZA₄]⁻ or [L]⁺[ZA₄]⁻  Formula 7 wherein, L is neutral Lewis acid;H is a hydrogen atom; Z is an element of Group 13; and A are eachindependently an aryl radical having 6 to 20 carbon atoms or an alkylradical having 1 to 20 carbon atoms, at least one hydrogen atom of whichis substituted with a halogen, an hydrocarbyl radical having 1 to 20carbon atoms, an alkoxy radical having 1 to 20 carbon atoms or phenoxyradical.
 8. The polypropylene-based resin composition of claim 1,wherein the polypropylene is a high crystal homopolypropylene, a blockcopolymer that includes ethylene or a mixture thereof.
 9. Thepolypropylene-based resin composition of claim 1, wherein the inorganicfiller is selected from the group consisting of talc, calcium carbonate,mica and clay.
 10. The polypropylene-based resin composition of claim 1,further comprising one or more additives selected from the groupconsisting of an antioxidant, a UV stabilizing agent, and a slip agent.11. A part for vehicles comprising the polypropylene-based resincomposition of claim
 1. 12. The part for vehicles of claim 11, whereinthe part for vehicles is selected from the group consisting of a bumpercover for vehicles, a glove box, and a pillar.